Color television



A. M L. NICOLSON COLOR TELEVISION Filed May 8, 1950 2 Sheets-Sheet l REC!" INVENTOR Alexander MELean N/co/san,

ATTORNEY,

March 14, 1933.

A. M L. NICOLSON COLOR TEJJZWISION 2 Sheets-Sheet 2 Filed May 8, 1930 (Red) .5r'Ca q]111D agar peed) (Val/0W) Na wg/ N/fo /5/ue) (5mg co K (Mei) I I Alexander MLeon Mao/son INVENTOR ATTORNEY Patented 1 Mar. 14, 1933 UNITED STATES PATENT OFFICE ALEXANDER MCLEAN NICOLSON, OF NEW YORK, N. Y., ASSIGNOR TO COMMUNICATION PATENTS, INC., 01: YORK, N. Y., A CORPORATION OF DELAWARE COLOR TELEVISION Application filed May 8, 1930. Serial No. 450,630.

This invention relates to the transmission and reception' of images over wires or through space, and particularly to the transmission of colored images or objects in their natural colors.

In the transmission of images or pictures it is necessary to illuminate the object in some manner. This may beaccomplished by scanning the object with a point of light, the reflection or projection of which will register the relative densities of light and shade of the object on a photoelectric cell. These relative densities of light will be transformed into corresponding electrical variations by means of the photoelectric cell which variations may be transmitted to receiving apparatus. It is well known that if these light variations are reproduced before the eye at the rate of 15 cycles per second or faster, they will appear as a picture of the object scanned by the transmitter.

In my copending application Ser. No. 397 826, filed October 7, 1929, now Patent No. 1,863,278, granted June 14, 1932, a system for the simultaneous transmission and reception of successive unit portions of a scene has been disclosed. In this patent an are traveling at a high rate'of speed between two polarized electrode rails in a magnetic field is employed as the scanning and reception medium. As this are illuminates unit areas of the scene to be transmitted, reflected light from the scene or object is impressed on a photoelectric cell and transformed into electrical vibrations. In the system disclosed in this patent, direct current energy is used to energize,

. the fields and direct current potential difi'erences to maintain the traveling arc.

In my copending application Serial No.

450,025, filed May 5, 1930, now Patent No.

1,839,696, granted Jan. 5, 1932, a television system operating in a similar manner, but

which is supplied entirely from an alternating current source isdisclosed. Either of the above systems may be employed for the actual transmission and reception of the colored images, the apparatus for which is the subject of the present disclosure.

An object of this invention is to accom plish .color television with transmitting and .ing system, substantially all the colors required to reproduce an object in its natural colors. 1

A further object of the invention is to transmit and receive the image of an object in its natural colors without the use of me chanical moving elements. i

The above objects are carried out by apparatus which gives to the are as it traverses the scanning or receiving screen, various colors which may range from red to indigo. The electrode rails, therefore, maybe made up of or coated with materials containing calcium, potassium, nickel, cobalt and others in successive units so as to impart to the arc and tinge it with a series of colors which primarily occur in all colored objects. Furthermore as'sodium,'when used as a photo cell element, is sensitive to white light, and to all the colors of the spectrumthat are visible, and is responsive to red, and potassium as a cell element is sensitive to blue and green, the photo cells may be chosen to select various colors.

The invention will be more fully understood by reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic view of a transmission system embodying the invention;

Fig. 2 is a perspective view of thescanning screen and its associate coils;

Figs. 3, 4, 5 and 6 are plan and perspective views of electrode rail arrangements for permitting'the scanning of an object with many colored light rays and the reception thereof; Fig. 7 is a diagrammatic chart of a rail system; and

Fig. 8 is a diagram of'a photoelectric cell.

trode rails 5 and 6 which have opposite polarities at any instant are shown with a foreshortened gap 7 at which an arc initiates. A

supply voltageforthe arc is obtained from a 40 transformer 40 for transmission to 51 master oscillator over conductors 8, the frequency of the master oscillator being maintained constant by the use of a crystal control 11. The piloting and Synchronizing impulses 5 are transmitted over conductors 12 to a syn chronizer 13, and from the electrode rail screen to the synchronizer over c'onductors14. This system may operate as a direct current field system such as disclosed in Patent No.

101,863,27 8, or'as an alternating current field system in accordance with the disclosure in 1 my Patent No. 1,839,696, mentioned above. A

driving field coil '17, preferably, of the spherical type is shown surrounding the electrode 1 rails 5 and 6 forming the scanning screen, the field beingsupplied from a source 18 shown as an alternating dur'rent source through a rectifier 19 over conductors 9. The source 18 further supplies energy to an anterior field 20 coil 20 and a posterior field coil 21, through phase shifters 22 and 23, respectively, and rectifiers 24 and 26 respectively. A control field P 30 is shown connected to the synchronizer13 through a transformer 31. As the arc is pfopagate over the rails 5 and 6, it projects light through a pinhole 33 in a camera anterior to the scanning screen, scanning objects in front thereof. The reflected light rays according to the colors of theobjects are impressed upon a photoelectric cell 35 or (plurality of cells which may be placed aroun the periphery of the screen. The current variations generated by the cell which correspond to the relative color variations of the object are amplified 85 by an am lifier 36 and transferred over conductors 3 toxa modulator oscillator system 38. .After modulation with a transmitting wave, these color transmitting fre uencies are.

fed into an. antenna system 39 t rough the distant I int." The-antenna system may be replaced y-.a wire on tem employing carrier currents 01 by an ordinarylo'w frequency wire system without the modulator-oscillator system. Simultaneously with the transmission of the color frequencies there is also impressed on the modulator-oscillator 38 over conductors 41 for transmission to the corresponding receiving apparatus, the iloting and synchronizing impulses and the ase illuminating freif the system is operated with an alternating current field.

The screen of F1 1 with its anterior, postenor and driving coils, is-shown more clear- 1y in'Fig. 2, mounted upon a base 44. Correponding elements have been designated by e same numerals as in Fig. 1 but having prime indicators. In Fig. 2 the screen is shown composed of rails 5 and 6', the turning qgortions of which are behind a frame 45 which efines the scanning portion of the transmitter or the image screen atthe receiver. It will be observed that the rails 5 and 6' are compound to the extent of com risingthree'difi ferent'elements inseries int e anterior, postcrior direction r and two different. elements in the'lateral direction. The are ropagat on of this electrode s stem'forms' a traverse from one material to another as shown b the cubes forming the rails, and then bac ward by posterior coil 21', then to the right by driving coil 17 and then forward by anterior coil'20. In this manner the arc is made to pass over all of the elements 7 reek pattern, that is, it is d-rlven from left to right by the field winding 17' for a suflicient period to comprising the rails, each of "which imparts to the are a distinct color. The rail 6' may be composed of a different series of materials from that of rail 5 or of the same series of materials, depending -upon the particular color spectrum desired.

Another method of obtaining a spectrum color effect is by using a single element electrode system of configurations as shown in Figs. 3, 4, 5 and 6. Fig. 3 shows the zigzag method of directing "the arc suchthat when it travels from point 50 to point 51, it will pass over eleven elements. The are in traveling 'over this path may scan only a small unit area of the object which is determined by the shortest distance between the points 50 and '51 and the focus of the camera. The

elements forming the rails maybe composed of anynumber of various materials in accordance with the invention as shown by the various types of cross hatching which ma represent the materials-or the colors obtain Fig. 3 may represent a plan view or a front view of a rail. Assuming that it-is a front I view, each rail will have this configuration when viewed from the front, but such a system will appear as a straight line when viewed from the top and as shown in Fig. 5. How"- ever, if the system appears from the top as shown in Fig. 3, then theelectrode rails will appear from the front a's-straight lines as.

shown in Fig. 5. Either system will produce the same results, since the propagatlon of the arc is so rapid that the particular path of travel of the arc is not observed,

; Fig. 4 shows -a scanning screen 1n which only alternate rails are of the zigza or trian- Tgular type'or in fact one rail is 0 this pattern since like horizontal portions are joined together. The are will follow the zigzag rail or difieren material. For instance 53 may be calcium, providing a red light; 54 may be of sodium, producing a yellow light; 55 may be cobalt, producing a blue light; 56 of potassium, producing a violet li ht; etc., when their opposite electrodes are 0 the same mate- 13 course, these elements will be used in the form of alloys or oxides and preferably as a coating.

In Fig. 6 the sine wave configuration for the electrodes is shown. This may be a top or elevational View of the rail. in the same manner as explained above in connection with Fig. 3. The purpose of this configuration is the same as that of Fig. 3, and that is to scan a unit area with many colors, in order to more accurately obtain a fine color definition for the image and reproduce the colors of the object more accurately. Perfect scanning would provide a means for producing all the colors on one area at one instant, and although this result has been substantially obtained in the system shown in Figs. 1 and 2, it is approached in a simpler manner in the rail systems using the single element electrode but with the diagonal or sine wave configuration as shown in Figs. 3,4, 5 and 6. No

posterior or anterior fields are required, the

are being driven only by its main driving field 17.

Referring now to the chart in Fig. 7, the

' elements producing the various coloring offects are shown together with the colors obtainable from a compound are which is formed from Various combinations of certain elements. For instance an are forming between calcium and strontium, or between calcium and calcium, will provide a red are, while the combination between calcium and sodium will produce orange light when an arc is formed. Again an are forming between nickel or' cobalt and sodium will produce white light. Now, when the arc is driven from the calcium electrodes to the sodium and nickel electrodes, therewill be -a variation from red to orange to white, as the arc retains the color given it from the electrode from which it has just been disconnected. So on to the other electrodes. The are between nickel and cobalt when containing the effect of sodium, will provide a purplish light, and the are between cobalt and potassium will provide indigo light. The are, therefore, as driven by the posterior and anterior fields will scan a unit area of the object with colored light ranging from red to indigo with the intermediate shades occurring as the combination effects are obtained from three or more electrode materials. 7

The compound are screen, therefore, of Fig. 2, may be made up of alternate materials as shown in Fig. 7, producing the spectrum of light just described. In this manner very small areas of the picture may be scanned with substantially all the colors, those which are present in the object being transmitted by the photoelectric cell into the color frequency variations corresponding to the color of the object scanned.

In Fig. 8 another embodiment of the invention is shown, in which an' object 65 may be either atranslucent colored motion picture film or an opaque object. Photoelectric'cells 66, 67, 68, and 69 are to be used when the object 65 is opaque to receive reflected light while photoelectric cells 71, 72, 73, 74, and are to be used when the object is translucent to receive projected light. A camera 77 is shown with its pinhole 78 together with a scanning rail system 79. This color system functions either by providing screens in front 'of the various photoelectric cells which are colored with the important colors so as to permit each cell to be sensitive to only one particular color, or by having the element of each cell responsive to an important color. In this manner the various colors of the objects are obtained from the selectivity of the photoelectric cells as the arc traverses the electrode system 79, and projectswhite light thereon. The electrode 79 is shown in the form of a zigzag rail as in Figs. 3 and 4, and may either project white light or be made up of varied elements which produce colored lights which will augment the color selectivity of the cells. Furthermore, Fig. 8 shows a shutter screen 8 which may be composed of a lattice work of rods or posts such that shadows may be obtained at the receiver. the use of this screen, the scanning rays are periodically obscured as the arc passes behind the rods. This screen may be used, also in frontof the system of Figs. 1 and 2, or on any similar system to produce this periodic shuttering effect, which will produce spatial shadows anterior to the scanning arc. Since the basic scanning action of the arc and the operation of the piloting and synchronizing impulses are the same as in the systems of my patent mentionedabm e, they will not be explained herein but the method of propagation of the are over the compound electrode rails is as follows:

Assuming that an arc has been initiated at thefront and to the right by theforce caused by the arc current fiowing in a magnetic field produced by the field winding 17. This field impulse is of a frequency and amplitude to progress the are one element distance during its positive half cycle for instance, from a calcium to a sodium element. The negative portion of field current is then eliminated by the rectifier 19, and the driving field impulse becomes zero. Immediately a magnetic field from the posterior coil 21 is applied, so phased by the phase shifter 23 that the arc will be driven toward the-rear of the screen and be tinged by the elements of cobalt and potassium for instance. This posterior coil impulse may have an amplitude of twice that of the main field impulse to drive the are twice the distance. The force of this impulse will be eliminated at the antinode by the rectifier 26 and the field winding 17 will be energized by the next positive cycle to drive the arc from one element to another on the back portion of the screen in the same manner as on the front of the screen. When this field impulse is of zero value, the anterior coil is energized through the phase shifter 22 and rectifier 24 to drive the are forward in the screen over other coloredelements. These interpose'd impulses, therefore, force the are to travel over all electrodesconsecutivelyy, and although the arc has actually progressed along the screen only one scanning unit, it has contacted with twelve elements. In this manner, many colors maybe projected on a single unit area for scanning purposes, one or more of the colors of which may appear in this unit area of the object.

The above are driving system may be varied by connecting the anterior and posterior coils 20 and 21, respectively, in series or parallel, so as to provide a quadrature field with re-' spect to driving coil 17. The coils 20 and 21, for highest efiiciency, should take the form of a single spherical coil such as coil 17 but this form is impractical because it will interfere with the field of view. However, with either the series or parallel arrangement of the coils in the form shown, a satisfactory approximation of the spherical coil may be had. Also, this arrangement permits the elimination of the rectifiers and phase shifters, since the resultant components from the quadrature fields will provide the necessary posterior and anterior driving forces.

. The are may produce a color spectrum varying from red to indigo,-as shown in Fig. 7.

. As .this spectrum is projected on a unit area ofthe object through the pinhole 33/ of the camera, the colored light corresponding to the color of the object will be reflected onto the photoelectriccell 35, the otherlight projections being absorbed by the object. The

cell will transform these impulses into electrical vibrations for transmission to the receiver. These impulses may be synchronized by, the synchronizer 13 in the same manner as in my patents. I

At the receiver, which has a screen of preferably the same form as that of the transmitters but of exactly the same color arrangement, the arc will have superimposed upon it the corresponding color impulse received from the photoelectric cell 35, causing a helghteningof the color which the recelver arc has at that instant; Since the colors of tioned patents, thereby obtaining two-way television.

The screen of Fig, 2 with the coloring materials arranged as shown in Fig. 7 isadapt- To obtain colored scanningrays, the ante rior-posterior coils, which are connected in series or parallehare energized so as to have a field flux in quadrature with the field flux obtained from the coil 17 to bow the are forward and backward. By this bowing the arc will be tinged with the various colors indicated in Fig. 7 by the merging of the ionized discharges. The colored spectrum of red to indigo will thus be projected on the object for scanning purposes as above explained.

At the receiver screen the output of the photoelectric cells will'be impressed on the anterior and posterior coils 20' and 21', re-

The arc without a',

spectively, which may be connected in series or parallel. In other words, the arc will'be driven transversely by the field coil 17 and toward the front and toward the rear of the screen by the photoelectric currents in the coils 20 and 21. The receiving arc will be bowed at the exact position of the scanning are at the transmitter, and in the same direction, thus coloring the image with the color of the object scanned. This is brought about by the two arcs being synchronized as described in the patents mentioned above, the

photoelectric cell being energized by the particular colored light corresponding to the position of the are at that time. A more positive action is obtained by superposing the photo cell currents onto a quadrature field current in the anterior and posterior coils. This method of receiving is similar to one embodiment of my receiving system disclosed in Patent #1363278, in which increased brightness of the arc is obtained by bowmg the arc toward the front. of the screen and nearer the observers eye and darkening'of the arc-is obtained by bowing the arc toward the back of the screenand away from the observers eye for contrast effect. The amount.

other scanned coloration. The eye will sub consciously mix detail "and color' to form a bright colored image.

mg colors, but it is adaptable to equivalent systems and is to be limited only by the scope of the appended claims.

What I claim as my invention is:

1. In a television system, means for producing an are for scanning an object, electrode rails for predetermining the path of said arc, means for moving said are, and means for imparting various colors to said arc.

2. ,In a television system, means for producing an arc, electrode rails for predetei mining the path of said are, and means for moving said are over color tingeing materials.

3. In a television system, means for producing an are for scanning an object, electrode rails for predetermining the path of said are, means for moving said arc, means for transmitting reflected light from said object, said means including a photo cell and means foractuating said cell with light corresponding to the color of said object.

4. In a television system, a transmitter scanning screen, means for producing an arc in said screen, said screen having electrode rails for determining the path of said are, means for moving said arc, a receiver comprising a receiving screen, means for producing an arc in said receiver screen, and means fortransmitting an image of said object in its natural colors for reproduction on said receiving screen.

5. In a television system comprising means for producing an are for scanning an ob ect,

- means for moving said arc, electrode rails for determining the path of said arc, means for scanning an object with said arc, areceiver comprising a receiver screen with a similar arc, and means for reproducing with said second arc an image of said object in its natural colors.

6. In a television system, a transmitter having a scanning screen and means for initiating an arc in said screen, said screen having electrode rails for determining the path ofsaid arc, means for moving said arc, a receiver having a receiving screen and means con .trolled by said first means for initiating an arc in said receiver screen, and means for coloring said transmitter and receiver arcs.

7. An illuminating screen comprising a colored arc path in a magnetic field, said are being formed from and determined by polarized electrode rails between which said arc is created.

8. An illuminating screen comprising an endless colored arc path in a magnetic 'eld, said are path being formed from and determined by polarized'electrode rails between which said are is created.

9. An illuminating screen comprising end-.

less rail electrodes supported in a magnetic field, said electrodes being composed of various color imparting materials and means for creating a moving are along said electrodes.

10. An illuminating screen comprising a plurality of rows of interconnected electrodes supported in a magnetic field, said rows bemg composed of different color lmpartlng materials and means for creating a moving arc along said electrodes.

11. An illuminous. screen comprising a gas arc path, polarized electrode rails, means for initiating a moving are on said rails, means for coloring said are, and means controlled by said are for regulating its speed of propagation.

14. In a television system comprising a master station and a subscribers station, a colored'arc screen having electrode rails between which said are is formed at each of said stations for transmitting objects there-- between in their natural color, and means for in tiating 1nv synchronism arc d1scharges from said screen.

15. In a television system comprising a master station and a su'bscribers station, an arc screen having electrode rails to determine the path of said are at each of said stations, means for initiating and synchronizing an arc discharge in each of said screens, said are discharge varying in color as it progresses on said screen, and means for maintaining said arcs in synchrony throughout their entire travel.

16. In a television system comprising a moving arc in a magnetic field, electrode rails between which said are is formed, said rails determining the'path of said arc, and means for coloring said are to project a spectrum of color on a unit area of an object.

17. In a television system, a pair of coniposite electrode rails forming adjacent paths, means for initiating an arc between said electrode rails, a plurality of flux producing coils for propagating said arc in different-directions over said electrode rails, means for directing light from said am in a definite pattern over an object, means for transforming the various colors of said object into electrical currents, and means for reproducing an image of said object in its natural colors on a similar arc electrode-screen.

18. In a television receiving system, an incoming line having signals thereon corresponding to the colors of an object and the transforming 'sai .sponding electrical current variations,means for transmitting said detected currents to. a

as a receiver,

intensity of said colors, an electrode rail system composed of 'difierent materials having an irregular path, means for creatin 'an are between said electrodes, a plurality 0 driving field'coils for drivin said are over said irregular path of sai electrodes, and 1'neans for impressing said incoming signals upon said electroderails for intensifying the color of said are in accordance with the colors of said object and their intensity.

19. In a. color television transmission system, a set of composite electrode rails forming adjacent paths, means for creating an are between said electrodes, a plurality of field drivin coils for propagating said are in an irregu ar manner over said electrode rails,

said are being colored in accordance with the material of said rails at any particular instant, meansfor projecting all of said colors on said object in a definite pattern, means for I detecting the vario s colors of the object and color pattern into corresimilar arc screen operatin V and means for mrpressmgt e received currents on said receiving screen to increasethe .color intensity of the receiver screen are and v create a colored image of said object.

20. In a television transmission system, a I v composite electrode rail arrangement having adjacent paths, means -for creating an are r between said electrode rails, and a plurality of field coils for driving said are in an irregular mannerflover said rails, said rails impartmg a plurality of colors to said are, means I associated with said apparatus for projecting all of said colors on each unit area of an obect, means for detectin the color'of each unit area and transforming said color in accordance with its intensity into corresponding current variations, means for transmitting said variations to a similar receiving arc screen, said receiving screen reproducing said object inits natural colors by an increase in its color at the respective positions on said. screen in accordance with the color of said object.

. 4 ALEXANDER IcLEAN NICOLSON. 

